Vibration absorbing device for portable machines

ABSTRACT

A vibration absorbing device for portable machines of the type accommodating a vibration generating source therein and having a front handle and a rear handle, wherein said front and rear handles are secured to the main body of the machine independently of each other and through resilient buffer members respectively, while the main body of the machine is provided with seats for the respective resilient buffer members on the rear and bottom walls thereof over regions extending transversely of the main body. The front handle extends transversely of the main body to surround one side surface of said main body, while the rear handle extends perpendicularly of said front handle. Each of the resilient buffer member is so designed so to provide sufficiently rigid connection between the respective handle and the main body.

[451 Oct. 24, 1972 [54] VIBRATEON ABSORBING DEVICE FOR PORTABLE MACHINES [72] Inventors: Torao Kobayashi; Masatoshi Sato,

both of Tokyo, Japan [73] Assignee: Kyoritsu Noki Co., Ltd., Tokyo,

Japan 22 Filed: July 12,1971' 211 Appl.No.: 161,729

[30] Foreign Application Priority Data March 9, 1971 Japan ..46/ 12620 [52] US. Cl ..l43/32 R, 173/162, 267/137 [51] int. Cl. ..B27b 17/02 [58] Field of Search ..143/32 R; 173/162, 139; 267/ 1 37 [56] References Cited UNITED STATES PATENTS 3,525,373 8/1970 Kobayashi ..143/32 R 3,637,029 1/1972 Sherwood et a1.....l43/32 R X Stihl et al. ..l43/32 R Frederickson 143/32 R X Primary Examiner-Donald R. Schran AttorneyKarl W. Flocks [57] ABSTRACT A vibration absorbing device for portable machines of the type accommodating a vibration generating source therein and having a front handle and a rear handle, wherein said front and rear handles are secured to the main body of the machine independently of each other and through resilient buffer members respectively, while the main body of the machine is provided with seats for the respective resilient buffer members on the rear and bottom walls thereof over regions extending transversely of the main body. The front handle extends transversely of the main body to surround one side surface of said main body, while the rear handle extends perpendicularly of said front handle. Each of the resilient buffer member is so designed so to provide sufficiently rigid connection between the respective handle and the main body.

1 Claim, 8 Drawing Figures PATENTEUHBI 24 1912 SHEET 1 0F 5' INVENTQRS ATTORNEY VIBRATION ABSORBING DEVICE FOR PORTABLE MACHINES This invention relates to a vibration absorbing device for portable machines, such as a chain saw, having a source of vibration accommodated therein, and more specifically to a vibration absorbing structure of said machines in which a machine operating handle is connected to the main body of the machine in a manner to absorb vibration.

In the operation of a portable machine having a source of vibration, such as a motor and a chain saw blade of a chain saw, accommodated therein, there has frequently been encountered the problem that the vibration transmitting to the body of the operator causes an undesirable efiect in the operators body. For this reason, various vibration absorbing means have been provided in this type of machine. However, the conventional vibration absorbing means had the shortcomings that the vibration absorbing effect is not necessarily sufficient or the provision of the vibration absorbing means provides inconvenience or an unsatisfactory result in the handling and operation of the machine.

The object of the present invention is to improve the securement of a handle to a portable machine of the type described and to provide a vibration absorbing device for said portable machine which minimizes the vibration transmitting to the operators body and thereby enables the operator to handle and operate the machine conveniently, safely and efficiently.

According to the invention there is provided a vibration absorbing device for portable machines of the type accommodating a vibration generating source therein and having a front handle and a rear handle, wherein said front handle has a substantially U-shape and is provided at the front portion of the main body of said machine extending from above the upper surface of said main body to the front end of the bottom surface of said main body in a manner to surround one side sur face of said main body with a predetermined space there-between, the lower end of said front handle being integrally fastly connected to the front end of a rigid bifurcate supporting member extending longitudinally along the bottom surface of said main body from the front end to the rear end thereof, said front handle being secured to the main body of the machine at three points, i.e., at the upper end of said handle, the lower end of said handle or the front end of said bifurcate supporting member and the rear end of said bifurcate supporting member, through. resilient buffer members, and said main body of the machine being provided on the bottom surface thereof with one or a plurality of seats for the respective buffer members at the lower end of said front handle or the front end of said bifurcate supporting member over a substantially rectangular region of a predetermined length extending transversely of said main body; and said rear handle has its upper front end secured to the upper portion of a rear wall of said main body and its lower rear end secured to a rear handle supporting member extending rearwardly from the lower portion of the rear wall of said main body respectively through resilient buffer members, said main body being provided on the upper portion of the rear wall thereof with one or a plurality of seats for the respective resilient buffer members over a substantially rectangular region of a predetermined length extending transversely of said main body; and said front and rear handles being thus secured to the'main body of the machine independently of each other.

The present invention will be described hereunder with reference to the embodiments thereof shown in the accompanying drawing. In the drawing,

FIG. 1 is aside view showing an'embodiment of the vibration absorbing device according to the invention, as applied to a chain saw, and illustrating the structure of each handle connecting portion, with buffer members shown in cross-section;

FIG. 2 is a front view illustrating the manner of connecting the front handle of the'chain saw shown in FIG.

FIGS. 3a and 3b are a top plan view and a side view respectively of the rear handle of the chain saw shown in FIG. 1; and

, FIGS. 4, 5, 6a and 6b are views, corresponding to FIGS. 1, 2, 3a and 3b respectively, showing another embodiment of the vibration absorbing device of the invention.

FIGS. 1 and 2 show an embodiment of the vibration absorbing device of the invention as applied to a chain saw which is used for cutting standing timbers. In the main body 1 of the machine (hereinafter referred to simply as main body) are disposed a motor 2 necessary for driving a chain saw blade 4 and equipments associated therewith. The chain saw blade 4 is driven on an endless path by the driving shaft of the motor along the edge of a guide plate 5 projecting to the right, as viewed in FIG. 1, from the main body 1, to cut the standing timber. Reference numeral 3 designates the axis of the driving shaft.

The main body 1 is provided-with a front handle 6 and a rear handle 7. The operator operates the chain saw while securely holding the chain saw by these handles. The handles 6, 7 are independently connected to the main body I through a buffer member to be described later. The front handle 6 has a U-shape extending from the front upper side to the bottom of the main body 1 in a manner to surround more than half of the entire periphery of said main body. The lower length of the handle 6 extending along the bottom of the main body 1 is fastly grasped by the front end of a bifurcate supporting member 8 in perpendicular relation thereto, said bifurcate supporting member 8 extending from the front portion to the rear portion of the main body along the center line of said main body. This bifurcate supporting member 8 has a rigidity sufficient to prevent, in cooperation with the front handle 6, an oscillatory movement of the main body 1 relative to said handle in a plane perpendicular to said handle during operation of the machine. The upper end of the front handle 6 is connected with a bracket 9 through an upper buffer member 10, which bracket is rigidly secured to the main body 1 by means of bolts 11 and extends upwards from said main body, whereby a space sufficient to the insertion of a hand is provided between the main body I and the handle. 0n the other hand, the lower end of the front handle 6 is connected to the main body 1 through a lower buffer member 14 within a lower seat 13 which is provided in the bottom wall of said main body 1 and extends in a substantially rectangular shape towards the axis 3 of the driving shaft. The rear end of the bifurcate supporting member 8 is secured to the rear wall of the main body 1 through a cylindrical buffer member 20 at a point near the root of a rear handle supporting member 24 which is integral with the rear wall of the main body and extends rearwardly therefrom.

The upper buffer member for the front handle, as shown in FIG. 2, consists of a pair of halves which are made of a resilient material, such as vibration insulating rubber, and integrally coupled together by rigid outer and inner annular plate members 10a, 10b. The annular plate member 10a is fitted in an annular recess formed in the bracket 9, while the reduced diameter end portion of the front handle 6 is inserted into the annular plate member 10b and fastly secured to the bracket 9 by means of a bolt 12. Thus, the upper buffer member 10 is positively secured to the front handle and the bracket. Reference numeral 10c designates an annular space which is formed when the halves of the upper buffer member 10 are coupled together.

The lower buffer member 14, similarto the upper buffer member 10, comprises a resilient body such as vibration insulating rubber, and rigid plate members 14a, 14b attached to the upper and lower sides of said resilient body, and has a sectorial shape in transverse cross-section as shown in FIG. 1 and a substantially rectangular shape in longitudinal cross-section as shown in FIG. 2, extending transversely of the main body 1. The buffer member 14 is fastly secured to the lower end of the front handle 6 by means of bolts 16 which are respectively screw-threaded into nuts provided on the inner surface of the lower plate member 14b and embedded in the resilient body. On the other hand, the upper plate member 14a is secured at its longitudinal ends to a casing of the main body 1 by means of bolts 17. Reference numeral 140 designates a recess formed in the resilient body for receiving a bolt 18 by which a sectional housing is assembled.

The buffer member 20 comprises a cylindrical resilient body made of such a material as rubber, plate members 21a and 21b attached integrally to the upper and lower surfaces of said cylindrical resilient body respectively, and externally threaded studs 22a and 22b extending integrally outwardly from the outer surfaces of said plate members 21a and 21b respectively. The rear wall of the main body 1 and the rear end of the bifurcate supporting member 8 are secured with each other through the buffer member 20 by tightly engaging nuts 23a, 23b on the threaded studs 22a, 22b respectively.

Since the upper end of the front handle 6 is supported by the bracket 9 through the buffer member 10 of the construction described above on the upper side of the main body 1, and the lower end thereof is supported by the supporting area, having a substantial width, at the lower front end of the main body 1, the front handle 6 is supported substantially in the fashion of three-point support. It is also supported at the lower portion of the rear wall of the main body 1 through the buffer member and the bifurcate supporting member 8 to which said handle is rigidly connected by a bolt 19. Therefore, it is possible to support the machine with stability during operation of said machine. Namely, when the machine is supported, the front handle 10 is plane passing through the center of gravity of the machine and, therefore, the weight of the machine is mainly supported by the front handle 10 during transportation and operation of the machine. In this case, a vertical oscillation of the machine relative to the front handle is limited by the bifurcate supporting member 8 extending longitudinally along the bottom of the main body, while a horizontal oscillation of the machine is limited by the transversely extending lower buffer member having a relative large supporting area. Thus, a suitable rigidity of the front handle necessary for supporting the machine can be obtained.

On the other hand, the rear handle 7, as shown in FIGS. 3a and 3b, has its front end secured to the main body 1 through a plurality (two in the embodiment shown) of buffer members 25 and corresponding seats for receiving said buffer members, said buffer members 25 being attached to said rear handle and spaced from each other ina direction parallel to the axis 3 of the driving shaft, and said seats being provided on the upper portion of the back side of the main body 1 at locations corresponding to said buffer members respectively. The other end of the rear handle 7 is coupled with the rear end of the rear handle supporting member 24 through a cylindrical bufi'er member 29. Thus, the rear handle 7 forms, in cooperation with the rear handle supporting member 24, a substantially U-shaped handle perpendicular to the front handle 6. This rear handle 7 serves mainly to establish the direction of the machine.

The upper buffer members 25, similar to the buffer members for the front handle 6, each comprises a resilient body made of such a material as rubber, and rigid plate members 25a, 25b attached to the front and back surfaces thereof, and are secured to the respective seats on the back side of the main body 1 by 'means of a bolt 28 which is inserted into a bore formed in the resilient body, and screw-threaded into said seat through said plate member 25a. Securement of these upper buffer members to the rear handle 7 is effected by tightening a nut 27 on a bolt 26 provided on each plate member 25b.

The buffer member 29 is identical in construction with the buffer member 20 for the front handle 6 and secured to the rear handle 7 and the supporting member 24 by the engagement between externally threaded studs and nuts.

Another embodiment of the present invention will be described hereunder with reference to FIGS. 4, 5, 6a and 6b.

This embodiment is slightly different from the preceding embodiment in respect of the construction of the buifer member provided at the lower end the front handle and the construction of the buffer member provided at the upper end of the front handle, the other construction being the same as in the preceding embodiment. In FIGS. 4, 5, 6a and 6b, same or corresponding parts are indicated by the same reference numerals.

In this embodiment, two buffer members 30 are provided at the lower end of the front handle 6, which are spaced from each other in a direction parallel to the axis of the driving shaft. To the lower end of the front handle 6 is connected, by means of bolts 34, a substantially T-shaped bifurcate supporting member 33 which consists of a section 33a extending from the lower end of said handle 6 transversely of the main body 1 and a section 33b integral with said section 33a and extending at right angles thereto up to the rear end of the main body 1. Each buffer member 30 is a cylindrical body having a rectangular cross-section and has plate members 30a, 30b integrally bonded to the upper and lower surfaces thereof respectively, and is secured to the main body 1 and the bifurcate supporting member by means of bolts 31, 32 at said plate members. Reference numeral 35 designates a bolt by which the sectional housing of the main body 1 is assembled. The rear handle 7 shown in FIGS. 6a and 6b is similar to that shown in FIGS. 3a and 3b, but different in that while the latter is provided with a plurality of transversely spaced buffer members, the former is provided with a transversely elongate rectangular buffer member 36. This rectangular buffer member 36 may alternatively be an annular buffer member having an elongate central opening 36c as indicated by the dotted line. The buffer member 36 comprises a resilient body and plate members 36a, 36b attached to the upper and lower surfaces thereof, and is secured to the rear handle 7 by means of a bolt 38 which is screw-threaded into a nut 37 fixed to the underside of an outward extention of the upper plate member 36a in register with a bolt-insertion hole 380, and the rear upper wall of the main body 1 by means of a bolt 39.

Although the rear handle buffer member shown in FIGS. 3a, 3b and that shown in FIGS. 6a, 6b are slightly different in construction as described above, either of them is supported at one point by the end of the rear handle supporting member and at a plurality of points (or at a portion which can be equally regarded as a plurality of points) by the seat on the main body 1. In other words, the buffer member 36 is supported in the fashion of three-point support and thus the rear handle 7 can be secured to the main body 1 with a suitable rigidity.

It will be obviously understood that in the two embodiments described above, the buffer member provided at the lower end of the front handle and the buffer member or members provided at the upper end of the rear handle may optionally be exchanged to obtain a desired vibration absorbing effect.

in short, according to the present invention the front and rear handles are independently connected to the main body through the fubber member or members, whereby the mechanical vibration generated by the driving equipments of the machine can be dispersed and absorbed by the respective handles. Further, since either handle can be supported on the main body of the machine substantially in the fashion of three-point support, a suitable rigidity can be imparted to the junction between the main body and each handle and hence a horizontal oscillation and a vertical oscillation of the main body during operation of the machine are restrained. Consequently, the movement and holding of the machine by the front handle and the directioning of the machine by the rear handle-can be facilitated, and a remarkable effect can be obtained in the operation of machine which could not be achieved by the conventional supporting device.

What is claimed is:

l. A vibration absorbing device for portable machines of the t accoanmodating a vibrati m generating source erem an having a front han le and a rear handle, wherein said front handle has a substantially U-shape and is provided at the front portion of the main body of said machine extending from above the upper surface of said main body to the front end of the bottom surface of said main body in a manner to surround one side surface of said main body with a predetermined space therebetween, the lower end of said front handle being integrally fastly connected to the front end of a rigid bifurcate supporting member extending longitudinally along the bottom surface of said main body from the front end to the rear end thereof, said front handle being secured to the main body of the machine at three points, i.e., at the upper end of said handle, the lower end of said handle or the front end of said bifurcate supporting member and the rear end of said bifurcate supporting member, through resilient buffer members, and said main body of the machine being provided on the bottom surface thereof with one or a plurality of seats for the respective buffer members at the lower end of said front handle or the front end of said bifurcate supporting member over a substantially rectangular region of a predetennined length extending transversely of said main body; and said rear handle has its upper front end secured to the upper portion of a rear wall of said main body and its lower rear end secured to a rear handle supporting member extending rearwardly from the lower portion of the rear wall of said main body respectively through resilient buffer members, said main body being provided on the upper portion of the rear wall thereof with one or a plurality of seats for the respective resilient buffer members over a substantially rectangular region of a predetermined length extending transversely of said main body; and said front and rear handles being thus secured to the main body of the machine independently of each other. 

1. A vibration absorbing device for portable machines of the type accommodating a vibration generating source therein and having a front handle and a rear handle, wherein said front handle has a substantially U-shape and is provided at the front portion of the main body of said machine extending from above the upper surface of said main body to the front end of the bottom surface of said main body in a manner to surround one side surface of said main body with a predetermined space therebetween, the lower end of said front handle being integrally fastly connected to the front end of a rigid bifurcate supporting member extending longitudinally along the bottom surface of said main body from the front end to the rear end thereof, said front handle being secured to the main body of the machine at three points, i.e., at the upper end of said handle, the lower end of said handle or the front end of said bifurcate supporting member and the rear end of said bifurcate supporting member, through resilient buffer members, and said main body of the machine being provided on the bottom surface thereof with one or a plurality of seats for the respective buffer members at the lower end of said front handle or the front end of said bifurcate supporting member over a substantially rectangular region of a predetermined length extending transversely of said main body; and said rear handle has its upper front end secured to the upper portion of a rear wall of said main body and its lower rear end secured to a rear handle supporting member extending rearwardly from the lower portion of the rear wall of said main body respectively through resilient buffer members, said main body being provided on the upper portion of the rear wall thereof with one or a plurality of seats for the respective resilient buffer members oveR a substantially rectangular region of a predetermined length extending transversely of said main body; and said front and rear handles being thus secured to the main body of the machine independently of each other. 